说明：  基于bp神经网络和elman神经网络的图像压缩，mat文件是训练好的压缩结果，方便调用，可以测出信噪比等参数，用gui界面显示
(Based on bp neural network and elman neural networks for image compression, mat file compression results are trained to facilitate the call, you can measure the signal to noise ratio and other parameters, with gui interface display)